Manufacture of higher alcohols



Sept 11, 1951 H. c. BLACK ET AL 2,567,541

MANUFACTURE OF HIGHER ALCOHOLS Filed July 26. ,1946

BOILINC-.v TANK Bf ai@ .4 T rok/ve Y Patented Sept. 114, 1.951

UNITED STATES PATENT OFFICE $567,541 oF HIGHER ALcoioLs oward G. Black,l Chicago, VIll., and William M. Leaders,- Houston, ',Iex., assignors to Swift & Company, Chicago,.lll., a corporation of Illinois 7 claims. 1

'Ihisinvention relatesv to a method forthe separation of higher alcohols from natural. waxes. Morey particularly it provides an improved process for the complete recovery of higher alcohols from saponied natural waxes. The invention will be described in connection 'with the recovery of cetyl alcohol from crudev sperm oil as representa'-A tively fallingv within the scope'of. the invention.

In the past, cetyl alcohol has' been produced from crude sperm oil and spermaceti by distille-f tion of thel alcoholl from the saponified crude oil or wax. Distillation temperatures of around 200 C. to 250 C. at 10 to 15 millimeters pressure are employed. Under these severe operating condi tions, the soapwhichfis formed during the saponilcation reaction harderis` and discolors tothe extent that extensive refining operations of the soap or of the fatty acids recoverable' therefrom are made necessary in order to obtain a usable product. Moreover,. the higher alcohol obtained by this distillation method is of relatively poor quality becausev of severe operatingA temperatures required and must be subjected to bleaching, refining, and deodorization to produce alcohol of suiciently high quality for use' as an emulsifying: agent in cosmetic products, which is one of the major uses for this material. The refining oper.`

ations, in addition. to being time-consuming, en-

tailsconsiderableloss.

An object of the-invention is to produce ahig'h quality higher alcoholby a low temperature p'roc`.v ess whereby extensive rening is unnecessary'.

Another object of the presentv invention is to provide a process for the separation of higher alcohols from saponied waxes under such conditonsthat theV soap or thev fatty acids recover-- able therefrom are readily usable and: free from polymerized and colored material.

A still further. object of' the invention. is vto provide a method whereby the` alcohols extract-- edfrom saponied waxes can be readily frac# tionated according to their degree of unsatura-Y tion.

In accordance with the invention, it iscon@ templated to saponify a natural wax with caustic alkali, such as sodium hydroxide, potassium hydroxide, or calcium hydroxide, to obtain amixture of soap and higher alcohol. This step is. effected with aminimum of water and at. elevatedtemperatures, usually exceeding. 230"v` F. The

saponied. mixture of soap and alcohol is then extracted with a normally gaseous hydrocarbon, such as propane,A -by introducing the saponiled mixture and4 solvent into an extraction zone wherein the. alcohols are dissolved. in. the liquid (Cl. 26o-643) propane andthe soap and moisture rapidly gravitate to they bottom of. the extraction vessel. The alcohol-propane solution, because of its alow specific gravity of about 0.5 to 0.6, depending. on temperature and pressure conditions, separates readily from thesoap and moisture. The solution of solvent and alcoholcan eis-'ther -be fractionated further at different temperatures and pressures or thealcohol canbe. recoveredA immediately by subjecting the solution toV a solvent recovery process. I

To further illustrate the operation. of. the ingvention, reference is made to the figure which schematically' represents one method of carrying out our invention. l

Referring to the figure,- spermv oil or. otherwaxy material may be introduced through line 3 into a soap kettlev l equipped with. a suitable heating coil 5. A sapcnifying` agent,` such as caustic soda solution` of about a- 40 .per cent con-- centratiom is introduced into kettler l tlirough line 4. An excess o f alkali, for example about 10 per cont. is used to ensure Completo saponev ication. The oiland caustic areboiledun 1l` complete sa-ponicationVV is obtained, which usuale' ly requires 4 to 6 hours. Thefsaponiiication reaction produots are then lodi through;- lino Sv to a soap; Stoch ,feed tank l whichl is. equipped with astoun- J'aoket or other suitable meansof Sup-A plaine heat. toA maintain thel .soapprooiuotnoix-r ture in suitable' condition for Dwnpilgr The. Soap Stock is Ipumped through lino Shy pump I0 into mixing zone l2. mixingzone l2 by pump I3 throughn lino. l5- 'Ihe amount off propano and the' temperature tnoroofrare preferably .Suohas1 to dissolve Sube stantially all of the alcohol liberated1 by they Saponinoation reaction. Solvent ratiop ofV about 3- toI 1` to 1-0- to l at temperatures` hoornI about c3 FL to Y1:509 with corresponding pressures of 22.5 to 3100 pounds'- por square inohto maintain theV solvent in, liouenod` condition.4 have been found tobeV satisfactory operating conditions inE the mixing zonen n w duced. intoV asettlingftower- `I'I through line. l3- wherein a rapid and complete-settling ofthe-soap, water,.and excess caustic-is accomplished. rEhe propane and alcohol* solution Withdrawn-'1 through line I9, While soap;` water, and' excessy causticsolution are removed from the.1 settling. zonel through: line. 2 0;'. Thef propane-alcdhot solue tion can=be1irnmediately talren through.- line. 2i'

to asolvent recovery unit` not-shown.- and the. Solvent stripped fromtho aloohoh Alternatively; the aloohol propano'solution ispumpedsthroushf 'vIhe mixed streams are introfr 3 line 22 by pump 23 through a heater 24 into the upper section of fractionation column 25. Additional propane is introduced simultaneously by pump 21 through the line 28 into the lower section of the fractionation tower, the amount of solvent varying from about to l to 40 to 1. The fractionation tower is maintained at temperature and pressure conditions such that a separation of the extracted alcohols into two fractions is obtained. Depending upon the desired fractionation, the temperature varies from about 160 F. to as much as about 205 F., with a cor-A perature gradient of from' about 3 to 8 F. is,

preferably maintained in the column. The overhead fraction which always contains the maf CII -' the preparation of highly purified cetyl alcohol jority of the solvent is withdrawn through line from the fractionation tower throughV line 33to' a smaller solvent recovery system not shown.

As an example of the operation of our invention, crude spermaceti, obtained by the cold pressing of sperm oil, having an iodine value of 30 and a saponifcation value of 126, was saponified by boiling with a 10 per cent excess of a 50 per cent caustic soda solution for 8 hours. The reaction product was then mixed with 5 volumes of liquid propane at a temperature of 120 F. and 275 pounds of pressure and introduced into a settling tower wherein a complete and rapid settling of the water, soap, and excess causticwas effected. The supernatant propane solution was withdrawn from the upper portion of the settling tower and-pumped into the upper portion-of a packed fractionation column, While an equal volume of propane was introduced into the lower third of the tower. A temperature gradient'of 4 F. was maintained throughout the column, the overhead take-off temperature being 194 F., and the bottom take-off temperature, 190 F. Under these conditions an overhead fraction containing about 40 per-cent of the alcohol and a majority of the solvent was obtained. Upon removal of the solvent, the alcohol in the overhead fraction had an iodine value of 2 and for all practical purposes was water-white and was substantially pure cetyl alcohol. -The higher alcohol in the lower phase `was substantially darker in color and had an iodine value of about 55.

As a further illustrative example of our invention, carnauba Wax of an iodine value of 13.5 and a saponification value of 82 was saponied by boiling with a 40 per cent excess of a 50 per cent solution of caustic potash. The saponifledmixture was mixed with 5 volumes of liquid propane at a temperature of 130 F. and a pressure of 300 pounds. The mixture was introduced into a settling zone to effect the separation of the water, soap, and excess caustic. The supernatant solution of higher alcohol in propane `was taken directly to a solvent recovery unit and the propane removed from the alcohols. The alcohols obtained showed a saponiiication value of about 1 and had an iodine value of 5.

TheV soap obtained from the settling process was sufficiently light in color to make it readily available for use in blending with regular kettle boiled soaps. In the present example, the soap from the rendered fat of the sperm whale.

In addition to propane, other solvents which show selective solvent action at temperatures and pressures near the critical points may be used. Examples of such solvents are ethane, butane, propylene, butylene, and mixtures of these solvents.

Obviously, many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. A process for the treatment of waxes containing saturated and unsaturated esterifled alcohols, which comprises, saponifying the wax to obtain soap and the alcohols, subjecting the saponification products while fluid in the presence of a liquefied normally gaseous hydrocarbon to an elevated temperature and superatmospheric pressure whereby two fractions are formed, the lower of said fractions containing soap and the other containing the alcohols, subjecting the latter fraction to increased pressure and temperature in the presence of additional liquefied normally gaseous hydrocarbon whereby two phases.

4'5'. claim 1 wherein the wax is spermaceti.

4. In a process of recovering substantially pure higher alcohols from natural waxes which have been saponified, the improvement which comprises: treating a saponified natural wax containing the higher alcohols, water, and excess alkali by admixing while in a fluid condition with a liquefied normally gaseous hydrocarbon, said liquefied hydrocarbon being a solvent for the higher alcohols without dissolving the saponied material, water, and excess alkali; separating the undissolved materials from the liquefied hydrocarbon solution containing the dissolved higher alcohols; contacting the said liquefied hydrocarbon solution with additional liquefied normally 'gaseous hydrocarbon in a fractionating zone at a temperature and pressure substantially greater than was employed in the admixing step to form upper and lower liquid phases, the upper' of said 'phases comprising the major proportion and caustic solution obtained was-used with ai liquid soap made by the saponification of an4 -20 blend of olive oil and coconut oil. Propane-settled soap was added to the soap kettle at the-beginning .of the soap boiling operation? the said higher alcohols from the said upper phase.

5. In a process of recovering substantially pure higher alcohols from natural waxes which have been saponied, the improvement which com-V prises: mixing a saponied natural wax containing the higher alcohols, water, and excess alkali v While in a fluid statewith from approximately.; three-tol ten times its volume of a liquefied nor' mally gaseous hydrocarbon at a temperature between approximately 100 F. and 150 F. at a pressure of between approximately 225 and 300 pounds per square inch, said liquefied hydrocarbon being a solvent for the higher alcohols without dissolving the saponied material, water, and excess alkali; separating the undissolved materials from the liquefied hydrocarbon solution containing the higher alcohols; contacting the said liqueed hydrocarbon solution with additional liqueed normally gaseous hydrocarbon in a fractionating Zone to increase the hydrocarbon ratio to between approximately :1 and 40:1 at a temperature of between approximately 160 F. and 205 F. and a pressure of between approximately 450 and 700 pounds per square inch to form upper and lower liquid phases, the upper of said phases comprising the major proportion of the liquefied hydrocarbon containing substantially pure higher alcohols; and recovering the said higher alcohols from the said upper phase.

6. In a process of recovering substantially pure cetyl alcohol from crude spermaceti which has been saponied, the improvement which comprises: mixing the saponied spermaceti containing cetyl alcohol, water, and excess alkali with approximately five times its volume of liqueed propane at a temperature of approximately 120 F. and a pressure of approximately 275 pounds per square inch; separating the liquefied propane solution containing a substantial proportion of the cetyl alcohol from the undissolved materials; contacting the said liqueed propane solution in a fractionating zone with approximately an equal volume of propane at a temperature of approximately 194 F. and a pressure of approximately 600 pounds per square inch to form upper and lower liquid phases, the upper of said phases comprising the major proportion of the propane containing substantially pure cetyl alcohol; and recovering substantially pure cetyl alcohol from the said upper phase.

7. In a process of recovering a higheralcohol from waxes containing an esterified'higher alcohol, the steps which comprise: saponiiying the wax with an alkali to form a soap and a higher alcohol, subjecting the aqueous saponied mixture while in the fluid state to treatment with a solvent comprised essentially of a liquelied normally gaseous hydrocarbon at an elevated temperature and superatmospheric pressure without altering the composition of the aqueous saponification mixture, thereby forming an upper phase which is relatively rich in a higher alcohol and a lower phase which is relatively rich in soap, and separating the respective phases.

HOWARD C. BLACK. WILLIAM M. LEADERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,985,871 Pungs et al Dec. 25, 1934 2,004,131 Reid June 11, 1935 2,193,321 Leithe Mar. 12, 1940 2,318,749 Buxton et al May 11, 1943 2,380,414 Buxton et al July 31, 1945 2,388,412 Hixson et al. Nov. 6, 1945 2,394,968 Van Orden Feb. 12, 1946 2,432,021 Larner Dec. 2, 1947 2,440,029 Tabor et al Apr. 20, 1948 FOREIGN PATENTS Number Country Date 439,128 Great Britain Nov. 29, 1935 OTHER REFERENCES Lang, Chem. Abstracts, vol. 28 (1934), page 259, extract from Pharm. Acta Helv, vol. 8 (1933), pages 165, 166. 

1. A PROCESS FOR THE TREATMENT OF WAXES CONTAINING SATURATED AND UNSATURATED ESTERIFIED ALCOHOLS, WHICH COMPRISES, SAPONIFYING THE WAX TO OBTAIN SOAP AND THE ALCOHOLS, SUBJECTING THE SAPONIFICATION PRODUCTS WHILE FLUID IN THE PRESENCE OF A LIQUEFIED NORMALLY GASEOUS HYDROCARBON TO AN ELEVATED TEMPERATURE AND SUPERATMOSPHERIC PRESSURE WHEREBY TWO FRACTIONS ARE FORMED, THE LOWER OF SAID FRACTIONS CONTAINING SOAP AND THE OTHER CONTAINING THE ALCOHOLS, SUBJECTING THE LATTER FRACTION TO INCREASED PRESSURE AND TEMPERATURE IN THE PRESENCE OF ADDITIONAL LIQUEFIED NORMALLY GASEOUS HYDROCARBON WHEREBY TOW PHASES ARE OBTAINED, THE UPPER OF WHICH IS RELATIVELY RICH IN SATURATED ALCOHOLS, AND SEPARATING THE PHASES. 